Early diagnosis of an infection in neutropenic cancer patients is critical for timely treatment. But the diagnosis of an infection in these patients, especially at an early stage, can be very challenging. Therefore, there is a great need for sensitive biomarkers that can rapidly predict an infection and provide possible outcomes. We have already reported that soluble decoy receptor 3 (DcR3) has the potential to be a clinically relevant biomarker of sepsis. To further investigate its value in predicting infections and sepsis in neutopenic cancer patients, we propose to measure DcR3 levels in a large number of archived sera collected from neutropenic cancer patients with and without an infection. Data will be analyzed to demonstrate both the diagnostic and the prognostic value of serum DcR3 in neutropenic infection/sepsis. Also, DcR3 values will be compared with those of PCT (procalcitonin), a clinically available biomarker of sepsis. The positive outcome of this study wil provide a direct justification for further developing our proprietary DcR3 immunoassay for future clinical use.